1. Department of Obstetrics and Gynecology, Kobe University Graduate School of Medicine, Kobe, Japan
2. Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
3. Department of Pediatrics and Child Health, Nihon University School of Medicine, Tokyo, Japan
4. Nadeshiko Ladies Hospital, Kobe, Japan
5. Research Center for Disease Control, Aisenkai Nichinan Hospital, Miyazaki, Japan